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Entry  Wednesday, March 28, 2018, 11:46, Laura Lambert, UO2/C, 40282-2, TARGET BOAT, In progress, Carbonizing first full length 1step UCx target 

 Wednesday, March 28, 2018, 11:35

D-shaped discs were cut from cast 2, the same as the last sample of 1stepUCx [see elog i.d. 197]

A 13mm punch was used to punch out discs from pre-cut strips using the old method.

The target consists of 195 discs with 8.1cm in length - all single discs, no packs.

195 x UO2/C discs = 19.79g

Graphite insert is placed inside a target boat with both endcaps on.

Boat previously coated with TaC and sintered.

Ta-target boat is wrapped with 3-layers of heat shield and installed in evap1 yesterday afternoon.

Chamber pumped down overnight.


 Wednesday, March 28, 2018, 13:33

IGP1 = 4.03e-7 Torr

Tapped up TGHT manually to 80A, 0.83V - waited 50min, vacuum started to drop/stabilize.

Continued to tap up manually to 430A, 4.22V

Started out slow with a rate of ~10A/5min, and slowly increased to a rate of ~10A/min as vacuum stabilized, slowing down again when reaching carbonization outgassing.

Auto ramp at 0.2A/min from 430A-520A.


Thursday, March 29, 2018, 10:04

Reached 520A around 2am.

TGHT = 520A, 5.13V

IGP1 = 1.74e-6 Torr

Initiated auto-cool this morning at a rate of 1.0A/min.


 

    Reply  Monday, April 09, 2018, 16:51, Laura Lambert, UO2/C, 40282-2, TARGET BOAT, Problems, Carbonizing first full length 1step UCx target evap1_trip.JPGevap1_trip_archive.JPG

Laura Lambert wrote:

 Wednesday, March 28, 2018, 11:35

D-shaped discs were cut from cast 2, the same as the last sample of 1stepUCx [see elog i.d. 197]

A 13mm punch was used to punch out discs from pre-cut strips using the old method.

The target consists of 195 discs with 8.1cm in length - all single discs, no packs.

195 x UO2/C discs = 19.79g

Graphite insert is placed inside a target boat with both endcaps on.

Boat previously coated with TaC and sintered.

Ta-target boat is wrapped with 3-layers of heat shield and installed in evap1 yesterday afternoon.

Chamber pumped down overnight.


 Wednesday, March 28, 2018, 13:33

IGP1 = 4.03e-7 Torr

Tapped up TGHT manually to 80A, 0.83V - waited 50min, vacuum started to drop/stabilize.

Continued to tap up manually to 430A, 4.22V

Started out slow with a rate of ~10A/5min, and slowly increased to a rate of ~10A/min as vacuum stabilized, slowing down again when reaching carbonization outgassing.

Auto ramp at 0.2A/min from 430A-520A.


Thursday, March 29, 2018, 10:04

Reached 520A around 2am.

TGHT = 520A, 5.13V

IGP1 = 1.74e-6 Torr

Initiated auto-cool this morning at a rate of 1.0A/min.


 

 Monday, April 09, 2018, 16:00

ISAC controls performed a PLC switch over compromising the nuclear ventilation controls WITHOUT NOTIFYING ME  

This is the 2nd time in a month this has happened without being notified.

Evap1 has therefore tripped.

During this switch there was a problem which caused the turn over to take even longer.

Sat here tapping reset until nuclear ventilation was 'back on'.

Vacuum proceeded to drop once the tests were complete, then started to spike again, nuc vent remained not ok after tests were done nuc vent ok.


 

    Reply  Monday, April 09, 2018, 16:53, Laura Lambert, UO2/C, 40282-2, TARGET BOAT, Problems resolved, Carbonizing first full length 1step UCx target 

Laura Lambert wrote:

Laura Lambert wrote:

 Wednesday, March 28, 2018, 11:35

D-shaped discs were cut from cast 2, the same as the last sample of 1stepUCx [see elog i.d. 197]

A 13mm punch was used to punch out discs from pre-cut strips using the old method.

The target consists of 195 discs with 8.1cm in length - all single discs, no packs.

195 x UO2/C discs = 19.79g

Graphite insert is placed inside a target boat with both endcaps on.

Boat previously coated with TaC and sintered.

Ta-target boat is wrapped with 3-layers of heat shield and installed in evap1 yesterday afternoon.

Chamber pumped down overnight.


 Wednesday, March 28, 2018, 13:33

IGP1 = 4.03e-7 Torr

Tapped up TGHT manually to 80A, 0.83V - waited 50min, vacuum started to drop/stabilize.

Continued to tap up manually to 430A, 4.22V

Started out slow with a rate of ~10A/5min, and slowly increased to a rate of ~10A/min as vacuum stabilized, slowing down again when reaching carbonization outgassing.

Auto ramp at 0.2A/min from 430A-520A.


Thursday, March 29, 2018, 10:04

Reached 520A around 2am.

TGHT = 520A, 5.13V

IGP1 = 1.74e-6 Torr

Initiated auto-cool this morning at a rate of 1.0A/min.


 

 Monday, April 09, 2018, 16:00

ISAC controls performed a PLC switch over compromising the nuclear ventilation controls WITHOUT NOTIFYING ME  

This is the 2nd time in a month this has happened without being notified.

Evap1 has therefore tripped.

During this switch there was a problem which caused the turn over to take even longer.

Sat here tapping reset until nuclear ventilation was 'back on'.

Vacuum proceeded to drop once the tests were complete, then started to spike again, nuc vent remained not ok after tests were done nuc vent ok.


 

 Monday, April 09, 2018, 16:52

Turns out I wasn't on a list of ppl who need to know about this test when I should be

They also didn't reset the alarms locally outside the hot lab so nuc vent remained not ok until this was reset.

IGP1 reached 0.027 Torr before nuc vent was ok and pumps were able to be turned back on 

Pumps back on IGP1 = 1.86e-5 Torr and still pumping down


 

    Reply  Tuesday, April 10, 2018, 14:49, Laura Lambert, UO2/C, 40282-2, TARGET BOAT, Done, Carbonizing first full length 1step UCx target 

Laura Lambert wrote:

Laura Lambert wrote:

Laura Lambert wrote:

 Wednesday, March 28, 2018, 11:35

D-shaped discs were cut from cast 2, the same as the last sample of 1stepUCx [see elog i.d. 197]

A 13mm punch was used to punch out discs from pre-cut strips using the old method.

The target consists of 195 discs with 8.1cm in length - all single discs, no packs.

195 x UO2/C discs = 19.79g

Graphite insert is placed inside a target boat with both endcaps on.

Boat previously coated with TaC and sintered.

Ta-target boat is wrapped with 3-layers of heat shield and installed in evap1 yesterday afternoon.

Chamber pumped down overnight.


 Wednesday, March 28, 2018, 13:33

IGP1 = 4.03e-7 Torr

Tapped up TGHT manually to 80A, 0.83V - waited 50min, vacuum started to drop/stabilize.

Continued to tap up manually to 430A, 4.22V

Started out slow with a rate of ~10A/5min, and slowly increased to a rate of ~10A/min as vacuum stabilized, slowing down again when reaching carbonization outgassing.

Auto ramp at 0.2A/min from 430A-520A.


Thursday, March 29, 2018, 10:04

Reached 520A around 2am.

TGHT = 520A, 5.13V

IGP1 = 1.74e-6 Torr

Initiated auto-cool this morning at a rate of 1.0A/min.


 

 Monday, April 09, 2018, 16:00

ISAC controls performed a PLC switch over compromising the nuclear ventilation controls WITHOUT NOTIFYING ME  

This is the 2nd time in a month this has happened without being notified.

Evap1 has therefore tripped.

During this switch there was a problem which caused the turn over to take even longer.

Sat here tapping reset until nuclear ventilation was 'back on'.

Vacuum proceeded to drop once the tests were complete, then started to spike again, nuc vent remained not ok after tests were done nuc vent ok.


 

 Monday, April 09, 2018, 16:52

Turns out I wasn't on a list of ppl who need to know about this test when I should be

They also didn't reset the alarms locally outside the hot lab so nuc vent remained not ok until this was reset.

IGP1 reached 0.027 Torr before nuc vent was ok and pumps were able to be turned back on 

Pumps back on IGP1 = 1.86e-5 Torr and still pumping down


 

 Tuesday, April 10, 2018, 14:46

Glove box fixed!

Vented in Argon and transferred to glove box.

Graphite insert has moved to within 1mm of the end of the left side of the boat.

This could have happened during removal from evap1, hard to tell.

Either way, clearly a looser fit of the graphite insert in the boat indicating possible shrinkage of graphite insert.


 

Entry  Tuesday, April 17, 2018, 12:45, Laura Lambert, UO2/C, 40282-2, TARGET BOAT, Done, Processing UC2Flk_20 

 Tuesday, April 17, 2018, 10:30

UO2/C green was prepared April 12th, 2018

The cast peeled off the glass nicely April 13th, 2018

Initial UO2 powder used = 50.56g (Inventory R-01032A, UO2 + bottle = 626.28g before use)

Graphite powder used = 10.38g

Green cast dried UO2/C + organic mass = 61.40g 

The green was rolled up and wrapped in a piece of graphite sheet.

The Ta-target boat was wrapped with 3-layers of heat shield [1 reused, 2 new] and installed in evap1 yesterday.

Chamber pumped down overnight.

IGP1 = 8.4e-7 Torr

Tapped up to 35A, 0.46V

Waited ~135min, vacuum stable.

IGP1 = 1.6e-5 Torr

Initiating auto-ramp at 0.2A/min

Target boat will be ramped up to 520A.

Vacuum limit stop at 3.0e-4 Torr, backing off at 6.0e-4 Torr.


 Wednesday, April 18, 2018, 09:21

IGP1 = 9.6e-6 Torr

TGHT = 245A, 2.10V

Vacuum stable, increasing ramping rate to 0.5A/min.


 Thursday, April 19, 2018, 08:35

IGP1 = 3.21e-6 Torr

Materials have finished carbonizing.

TGHT = 520A, 4.97V

Evap1 has remained at max setpoints for ~6.5hrs

Initiating auto-cool at 1.0A/min


 Thursday, May 10, 2018, 10:33

Materials were vented in Ar and transferred to glove box on April 20th


 

Entry  Wednesday, March 23, 2011, 18:23, John Wong, , , , , Diffusion Bonding of Ta Fins for FEBIAD HP-A (w.o#38481-4) grab.K18246.pnggrab.g20718.pnggrab.r27097.pnggrab.t30095.png

March 23, 2011

12:30: Target oven is wrapped with 3 Ta-heat shields.  Pumping down evaporator

18:24: IEVAPIG1 is reading at 4.55e-6 Torr.  The p/s will be turned on tomorrow since there is no ISAC Ops on site. 

March 24

11:57: Evaporator has pumped down over night.  Vacuum @ 2.01e-6 Torr.  

14:42: TGHT @ 20A, Vac @ 1.65e-6 Torr.

14:52: TGHT @ 40A, Vac @ 1.66e-6 Torr.

14:52: Auto Heating begins: TGHT to max 820A.  Incrementing if vac < 4.5e-5 Torr, backing off if vac > 6.5e-5 Torr.

 16:04: TGHT @ 181A, vac @ 7.59e-6 Torr.

18:03: TGHT @ 420A, vac @ 4.71e-6 Torr.   (See attachment 2 for TGHT/IG1 for the past 4 hours)

March 25,

11:15:  TGHT has been at 820A for 14hr.  Vac @ 4.27e-6 Torr.  (See attachement 3 for TGHT/IG1 for these past hours)

11:17:  Auto cooling down is in progress...

17:21:  Auto cooling down ended at TGHT ~100A.  The TGHT was tabbed down manually from 100A to zero.  (See attachment #4 for the cooling down progress)

    Reply  Friday, March 25, 2011, 17:22, John Wong, , , , , Diffusion Bonding of Ta Fins for FEBIAD HP-A (w.o#38481-4) 

John Wong wrote:

March 23, 2011

12:30: Pumping down evaporator

18:24: IEVAPIG1 is reading at 4.55e-6 Torr.  The p/s will be turned on tomorrow since there is no ISAC Ops on site. 

March 24

11:57: Evaporator has pumped down over night.  Vacuum @ 2.01e-6 Torr.  

14:42: TGHT @ 20A, Vac @ 1.65e-6 Torr.

14:52: TGHT @ 40A, Vac @ 1.66e-6 Torr.

14:52: Auto Heating begins: TGHT to max 820A.  Incrementing if vac < 4.5e-5 Torr, backing off if vac > 6.5e-5 Torr.

 16:04: TGHT @ 181A, vac @ 7.59e-6 Torr.

18:03: TGHT @ 420A, vac @ 4.71e-6 Torr.   (See attachment 2 for TGHT/IG1 for the past 4 hours)

March 25,

11:15:  TGHT has been at 820A for 14hr.  Vac @ 4.27e-6 Torr.  (See attachement 3 for TGHT/IG1 for these past hours)

11:17:  Auto cooling down is in progress...

17:21:  Auto cooling down ended at TGHT ~100A.  The TGHT was tabbed down manually from 100A to zero.  (See attachment #4 for the cooling down progress)

 All the pumps are off.  The evaporator will be vented next week. 

Entry  Monday, March 28, 2011, 12:29, John Wong, Empty, 38481-8, HP-FEBIAD, Done, Fins diffusion bonding  grab.Kxr912.pnggrab.L10194.png

March 28, 2011

12:28:  Target oven is wrapped with 3 Ta-heat shields.  Pumping down evaporator

March 29,

12:14  Evaporator has been pumped down over night.  Vac @ 1.74e-6 Torr. 

12:24  TGHT @ 20A, Vac @ 1.66e-6 Torr.

12:29  TGHT @ 40A, Vac @ 1.56e-6 Torr.

12:30  Auto heating begins,  Paramenter Setup:  TGHT: 2A/min -->  max 820A.  Incrementing if Vac < 4.5e-5 Torr; backing off if vac > 6.5e-5 Torr.

18:37  TGHT @ 772A/7.395V  (see attachment#1 for the striptool).  Auto heating will stop when the TGHT gets to 820A, and the current will stay there over night. 

March 30

11:31 TGHT has been at 820A/7.8V for the past 17 hours.  (See attachment#2 for the striptool details.)

11:34 Auto-cooling beings

19:40 Auto-cooling has finished. TGHT is at zero and p/s has turned off.  Cooling water has stopped running.  Evaporator will be vented tomorrow.

March 31, 2011

11:13:  Venting evaporator.  All pumps are off and TGHT p/s has turned off. 

Thu Mar 31 11:57:20 2011 After removing the target from the evaporator,  some white coating (could be Tantalum oxide?) was found on the copper plate of the evaporator.  The white coating was found to have more on the left end side of the target and some just below the transfer tube.  The white coating was wiped off but it showed black residual on the wipers.  The target over looks fine.  Marik was informed, and we think this white coating could be  the organic substance burnt off from the target or the Tantalum oxide from the re-used Ta heat shields. 

 

Entry  Tuesday, April 05, 2011, 10:37, John Wong, Empty, 38481-6, HP-FEBIAD, Done, Fins diffusion bonding  pumping_down.jpgheatingup.jpgcooling_down.jpg

Tue Apr 5 10:36:53 2011:  Target oven is wrapped with 3 Ta-heat shields.  The evaporator is in the process of pumping down. 

Tue Apr 5 14:54:00 2011:  Evap has been pumped down for over 4 hours.  Vac is currently at 5.5e-6 Torr. (See Attachment#1)

Tue Apr 5 15:16:31 2011: TGHT is turned on.  Set  @ 20A/0.102V; panel reads 18A.  Vac @ 4.62e-6 Torr. 

Tue Apr 5 15:18:16 2011: TGHT set @ 40A/0.216V; panel reads 37A.  Vac @ 4.63e-6 Torr. 

Tue Apr 5 15:19:03 2011: Start Auto-heating.  Parameter setup:  TGHT rate @ 2A/min --> 820A max.  Incrementing if vac <4.5e-5 Torr, and backing off if vac >6.5e-5 Torr.

 Wed Apr 6 09:18:22 2011: TGHT was left at the auto- heating mode over night and  had been at 850A for about 12hrs; Vac @ 4.36e-6 Torr.  (see Attachment#2) 

Wed Apr 6 09:20:53 2011: Auto-cooling down has just started. 

Wed Apr 6 15:33:51 2011:  Auto-cooling completed.  (see Attachment #3 for the overall process)

Wed Apr 6 15:37:10 2011: TGHT p/s off, Venting evaporator. 

 

Entry  Wednesday, April 06, 2011, 17:07, John Wong, Empty, 37978-1, HP-FEBIAD, Done, Fins diffusion bonding  pumping_down.jpgAutoheating_parameter_setup.jpgcooling_down.jpg

Wed Apr 6 17:06:56 2011: Target oven is wrapped with 3 Ta-heat shields.  Pumping down evaporator in progress.

Thu Apr 7 09:32:36 2011: Evaporator has been pumped down for over 16 hrs, vac @ 1.74e-6 Torr (see attachment#1).   Target heater is turned on and about to ramp up.

 Thu Apr 7 09:37:11 2011: TGHT @ 20A/0.071V, panel reads 18A.

Thu Apr 7 09:38:16 2011: TGHT @ 40A/0.147V, panel reads 37A.

Thu Apr 7 09:40:53 2011:  Auto-heating begins.  (See attachment#2 for Parameter Setup)

Fri Apr 8 10:08:07 2011:  Auto-cooling process began last night at 8:30pm.  Instructions were given to the on shift ISAC-Ops to being the auto cooling.  The process was finished this morning at around 3am.  (See attachment#3 for the cooling down process).  The evaporator p/s is off and ready to be vented.

 

 

Entry  Friday, April 08, 2011, 14:55, John Wong, Empty, 38295-8, HP-FEBIAD, Done, Fins diffusion bonding  pumping_down.jpgAutoheating_parameter_setup.jpgcooling_down.jpg

Fri Apr 8 14:51:37 2011:  Target is wrapped with 3 Ta-heat shields.  The evaporator has been pumped down for over 4 hrs, currently vac @ 2.8e-6 Torr.  (See attachment #1, note: the drops in the IG1 reading were due to Controls group helping to fix the alarm handler notifications for the pagers.)

 Fri Apr 8 14:56:21 2011:  TGHT @ 20A/0.079V, panel reads 18V.   Vac @ 2.73e-6 Torr.

Fri Apr 8 14:57:42 2011: TGHT @ 40A/0.165V, panel reads 18A.  Vac @ 2.73e-6 Torr. 

Fri Apr 8 14:59:51 2011: Auto heating begins.  (See Attachment#2 for the parameter setup).  The target heater will read to 820A at 21:30.  ISAC Ops will help to cool down the target at around 05:00 on Saturday; instructions will be given.

Mon Apr 11 09:37:40 2011:  Target was cooling on last Saturday April 9 by the help from ISAC Ops.  (See Attachment#3 for the cooling down process).

Mon Apr 11 09:42:09 2011 :  Evaporator is vented.

 

 

 

Entry  Monday, April 11, 2011, 10:22, John Wong, Empty, 38295-9, HP-FEBIAD, Done, Fins diffusion bonding  pumping_down.jpgAutoheating_parameter_setup.jpggrab.A29589.png

Mon Apr 11 10:21:56 2011: Target is wrapped with 3 Ta-heat shields.  Evaporator is pumping down. 

Mon Apr 11 14:34:32 2011:  Evaporator has been pumped down for over 4 hours.  Vac @ 2.83e-6 Torr.  (see attachment#1 for pumping down process).

Mon Apr 11 14:38:05 2011:  Auto heating beings.  (see attchement#2 for the parameter setup)

Mon Apr 11 17:06:51 2011:  Auto heating is in process,  TGHT @ 324A/2.031V.  The target heater should reach at the max 820A at around 21:30 and will remain at that current for at least 3 to 4 hours.  ISAC Ops will help start the auto-cooling tomorrow at 03:00.

 Tue Apr 12 09:43:46 2011:  Auto cooling down process ended. TGHT stayed at 820A for about 5.5 hrs.  (see attchment# for cooling down process).

Tue Apr 12 09:59:43 2011: Pumps and p/s off, evaporator vented.

Entry  Tuesday, April 12, 2011, 10:30, John Wong, Empty, 38481-5, HP-FEBIAD, Done, Fins diffusion bonding  grab.s31535.pnggrab.c31573.pngcooling_down.jpg

Tue Apr 12 10:29:38 2011:  Target wrapped with 3 Ta-heat shields.  Evaporator is currently being pumped down.

Tue Apr 12 15:03:55 2011:  Evaporator has been pumped down for over 4 hrs.  Set TGHT @ 20A/ 0.066V, Vac @ 2.46e-6 Torr. (See Attachment#1 pumping down process).

Tue Apr 12 15:05:11 2011: TGHT @ 40A/0.142V, VAc @ 2.46e-6 Torr. 

Tue Apr 12 15:14:16 2011  Auto heating process begins (See attachment #2 for the parameter setup).  TGHT will reach to 820A max at around 21:45 and the current will stay there for at least 4 hours.  Instructions have given to ISAC Ops to being the auto-cooling down process tomorrow at 03:00 

Wed Apr 13 10:00:13 2011:  TGHT reached to 820A max and stayed for about 5 hrs before the cooling process begun (see Attachment#2: Cooling down process). 

Wed Apr 13 10:04:19 2011: p/s is now off and evaporator is now vented. 

 

 

 

 

 

Entry  Wednesday, April 13, 2011, 10:37, John Wong, Empty, 38481-7, HP-FEBIAD, Done, Diffusion bonding of Ta Fins for FEBIAD-HP pumping_down.jpgAutoheating_parameter_setup.jpgcooling_down.jpgwasher_on_target_leg.jpg

Wed Apr 13 10:37:25 2011:  Target is wrapped with 3 Ta-heat shields.  Evaporator is currently being pumped down.

Wed Apr 13 15:28:02 2011:  Evaporator has been pumped down for over 5 hrs.  Vac @ 2.38e-6 Torr.  (See attachment1: Pumping process)

Wed Apr 13 15:29:21 2011: Set TGHT @ 20A/0.074V, Vac 2.98e-6 Torr.

Wed Apr 13 15:30:00 2011: Set TGHT @ 40A/0.158V, Vac @ 2.30e-6 Torr. 

Wed Apr 13 15:37:42 2011:  Auto heating begins.  TGHT will increase to 820A by 2A/min.  Cooling down will take after the current has stayed at 820A for at least 4 to 5 hrs.   ISAC Ops will help to start the cooling process on April 14 at 03:00.  (See attachment#2: Parameter Setup).

Thu Apr 14 09:49:31 2011:  TGHT reached to 820A and stayed there for about 5.5 hrs.  ISAC Ops helped to start the cooling process (see attachment3: Cooling process).  The target is ready to come out from the evaporator.   P/S is off and evaporator is vented.

Mon Apr 18 12:18:55 2011:  A problem with the bolt and washer occurred during the fin diffusion bonding.  (See attachment #1 and Message ID#15 for more details) .  This target needs to be repaired.

 

 

 

Entry  Thursday, April 14, 2011, 09:53, John Wong, Empty, 37810-1, HP-FEBIAD, Done, Fins Diffusion bonding  cooling_down.jpg

Thu Apr 14 09:52:59 2011: Target is wrapped with 3-Ta heat shield and ready to go into the evaporator. 

Thu Apr 14 11:57:29 2011: The process is on hold until the problem with the screw and the washer of the evaporator is resolved.  See ID#15 for more details.

Fri Apr 15 11:22:27 2011:  The shorter fully threaded bolts and un-threaded washer are being used. 

Fri Apr 15 11:23:30 2011:  Target is in the evaporator and ready for the fin diffusion bonding.  The evaporator is currently being pumped down.

Fri Apr 15 15:57:40 2011: TGHT @ 20A, Vac @ 4.53e-6 Torr.  ISAC Ops will help to start the auto heating process at 18:00hr tonight  and  begin the auto cooling on April 16 @ 18:00 hr. 

 Mon Apr 18 10:53:39 2011:  Target was heated @ 820A over the weekend and pumped down on Saturday April 16 in the evening.  P/S is off and evaporator is vented.  (see Attachment#1 for the striptool)

Mon Apr 18 12:16:22 2011:  Target fin diffusion bonding is nicely done, and the evaporator shows no sign of any coating.  It looks like the problem from the bolts and washers is resolved.  

Entry  Thursday, April 14, 2011, 17:03, John Wong, Empty, 38481-7, HP-FEBIAD, Problems resolved, Evap. bolt/washer problems & solutions 6x

 Thu Apr 14 14:03:17 2011:  What did we see after the fin diffusion bonding of Ta fins for FEBIAD-HP (w.o#38481-7) ? :

1.  A problem occurred during the FEBIAD HP Ta fin diffusion bonding and was discovered after the evaporator chamber was opened.  The washer was "wielded" on to the left leg of the target (see attachment #1: washer on target leg). 

2. A look inside the evaporator chamber shows that more coating is found on the evaporator lid and the copper base plate (See attachment#2: Inside evap chamber). This coating was previously found when a HP FEBIAD target underwent for the fin diffusion bonding (See Message ID#4: Diffusion bonding of Ta Fins for FEBIAD-HP (w.o#38481-8)).  The evaporator chamber is cleaned with a wiper sheet and EtOH each time before a target is put in;  however the coating is not easily removed and there are always some residual remain. 

3.  The bolt and the washer are deformed.  The top part of the bolt is expended and can no longer fit into the threaded washer  (See attachment#3: Deformed bolt_washer). 

4.  The TIS group was called in to investigate the problem.  It was believed that the problem might have started from the bolts and the washers.  The un-threaded shank bolts and the threaded washers are made for remote handling purposes, so they do not fall apart everywhere in the hotcell.  However, if these bolts and the washers are used for the evaporator, which are bolted on and tighten against the gravity onto the conductors, this may create a gap if the threaded washer is tilted slightly.  (See attachment#4: Gap).  As a result, this causes an uneven pressure contact of the bolt/washer and the target leg.  

Solutions:

Use fully threaded bolts (same material as before - a mild steel) and remove the threads from the washers (See attachment#5: No Gap).

--> To be tested...

 Fri Apr 15 11:59:31 2011: 

The new bolts/washer were cleaned only with simple green and ultrasonic for 5 min.  The bolts and washer should not be cleaned for too long; some remaining grease actually helps prevent them from getting rusty.  The evaporator is wiped with EtOH and  the target is inside.  The bolts and washers are tighten and they are not showing at space like before (See attachment#6: new bolt_washer) .  The evaporator is being pumped down and the target heater will be raised to 820A; we will have to wait until the fin diffusion bonding is complete and the evaporator chamber is vented. 

 Mon Apr 18 12:30:35 2011: 

After a fin diffusion bonding of a HP FEBIAD target, there is no sign of coating in the evaporator.  The bolts/washer and the target look normal. 

--> The problem is solved.

Entry  Monday, April 18, 2011, 18:14, John Wong, Empty, 38295-8, HP-FEBIAD, Problems, Sintering target oven coated with TaC pumping_down.jpgAutoheating_parameter_setup.jpgvac_curve.jpgoverall_process.jpgoverall_process_2.jpg

Mon Apr 18 18:10:53 2011: 

FEBIAD-HP target (w.o 38295-8) is coated with TaC (previously prepared on Feb 15, 2011).  This target will be used for the SiC run in Oct, 2011.  The target is wrapped with 3 Ta-heat shields and is in the evaporator.  Pumping down of the evaporator is in process, currently vac @ 3.66e-5 Torr.   

Tue Apr 19 11:00:36 2011: Evaporator has been pumped down over night (~17hrs).  Vac is currently at 1.84e-6 Torr (See Attachment#1: pumping down curve).

Tue Apr 19 11:09:49 2011: TGHT @ 30A/0.086V, Vac @ 1.82e-6 Torr.

Tue Apr 19 11:13:05 2011: TGHT @ 60A/0.184V, Vac @ 1.75e-6 Torr.

Tue Apr 19 11:14:06 2011: Auto-heating will begin @ 0.5A/min until vacuum is stable then the auto ramping rate will increase. (See Attachment#2: parameter setup).

Tue Apr 19 14:27:08 2011:  TGHT is currently at 148A/0.65V, vac @ 1.92e-5 Torr.  The pressure spiked up to 7.7e-5 Torr (trip @ 8e-5 Torr) at ~124A.  The current was lowered down to 120A to allow the pressure to come down (See Attachment#3: Vac_curve).   Auto-heating rate has changed to 1A/min. 

Wed Apr 20 10:08:52 2011:  TGHT reached to 700A and stayed for about 5 hours.  ISAC Ops helped to start the auto cooling down process.  (See Attachment#3: Overall Process). 

Tue Apr 26 11:12:36 2011

Result:  The dried coating isn't looking the same like the rest of the target.  Typically, the finished coating looks gray.  But a layer (or line) of light brown coating can been seen from one end of the target to the other end. 

--> This target was heated up to 700A.  Will try to re-heat this again to 820A. 

 

Re-heating the Target

Tue Apr 26 12:44:30 2011:  Target is wrapped with 3 Ta-heat shield and is in the evaporator which is currently being pumped down. 

Tue Apr 26 17:39:40 2011:  TGHT was tapped up to 70A before began with auto-heating @ 2A/min to 820A max.  Currently TGHT at 204A/1.0V, Vac @ 3.97e-6 Torr.  ISAC Ops will help to start auto cooling at 04:00 on April 27.

Wed Apr 27 12:26:41 2011: Auto cooling completed.  P/S off and evaporator is vented, (See Attachment#5: Overall Process_2).  Target oven looks good; finished surface looks gray, as expected. 

 

Entry  Wednesday, April 20, 2011, 16:42, John Wong, Empty, 38481-8, HP-FEBIAD, Done, Sintering target oven coated with TaC overall_process.jpg

Wed Apr 20 16:39:46 2011:  Target oven was coated with TaC early today.  The target was allowed to dry and then wrapped with 3 Ta heat-shields.  The target is in the evaporator and it is being pumped down.  Vac is currently at 9.48e-6 Torr. 

Wed Apr 20 17:51:12 2011 : TGHT @ 60A/0.225V, Vac @ 5.98e-6 Torr. 

Wed Apr 20 18:20:04 2011: Auto-heating begins @ 0.5A/min to max of 820A.

Thu Apr 21 10:12:34 2011: TGHT was auto ramping up slowly over night to 546A this morning.  The ramping rate has changed to 2A/min since the vacuuum is stable at ~3.9e-6 Torr.

 Tue Apr 26 11:10:03 2011:  TGHT reached to 820A max on April 21 and stayed at that current for a few hours.  ISAC Ops helped to ramped down the heater afterward.  (See attachment#1: Overall Process).

Result:  Good!  TaC is coated evenly on the target. 

 

 

 

Entry  Monday, May 09, 2011, 16:10, John Wong, Empty, 38817-1, HP-SIS, Done, Diffusion bonding of Ta Fins TGHT_ramping_up.gifoverall_process.jpg

Mon May 9 16:09:35 2011:  Target is wrapped with 3 Ta heatshields and the evaporator is begin pumped down.

Mon May 9 17:59:57 2011:  Vac is @ 1.33e-5 Torr.  TGHT was stepped up to 60A before starting the auto heating process (See Attachment#1: TGHT_ramping_up).   Note: Although the vacuum is at low e-5 torr, this should be fine to start the TGHT because it takes a while to heat up the high power target.

Tue May 10 11:10:44 2011:  TGHT reached to 820A and stayed for 4 hrs before ISAC Ops helped to begin the cooling process.  (See Attachment#2: Overall process).

Entry  Tuesday, May 10, 2011, 14:58, John Wong, Empty, 38817-2, HP-SIS, Done, Diffusion bonding of Ta Fins for HP-SIS (w.o#38817-2)  starting_process.jpgoverall_process.gif

Tue May 10 14:56:05 2011:  Target is wrapped with 3 heat-shields.  The evaporator is pumping down, vac @ 4.72e-6 Torr.  TGHT was raised to 60A/0.239V.  Auto heating will being now; THGT will be ramped up to 820A @ 2A/min. (See Attachment#1: Staring_process)

Wed May 11 10:16:03 2011: Auto cooling was started by ISAC Ops' help.  TGHT has ramped down to zero.  The p/s will be turned off and the evaporator will be vented soon. (See Attachment#2: Overall Process).

 

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